JPH09181140A - Semiconductor integrated circuit assembly inspection equipment and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easily detecting an imperfect bonding state wherein a lead levitates slightly from a bump, in the inspection of a junction part after ILB (inner lead bonding) of TAB technique. SOLUTION: A semiconductor chip 1 is fixed by a stage 6, and leads 3 (3a, 3b) of a TAB tape held by a retaining part 7 are connected with bumps 2 on the chip 1. A CCD camera 5 is installed above the chip 1, and the stage 6 is subjected to movement control in the vertical direction by a movement control mechanism 8. The camera 5 obtains the connection state after ILB wherein the leads 3 are connected with the bumps 2, as first image data, and obtains the connection state of the leads 3 and the bumps 2 in a different positional relation, as second image data. The different positional relation is obtained, e.g. after the stage 6 is moved by the movement control mechanism 8 and only the chip 1 is slightly moved downward. By comparing the image data, the quality of connection state is judged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and an inspection apparatus for a connection state between a lead electrode and a bump after bonding used in a TAB technique.

[0002]

2. Description of the Related Art As a method for detecting whether or not inner leads are normally joined to bumps after ILB (Inner Lead Bonding), image data is captured using a CCD camera, bumps and leads are recognized, and their positions are displaced. There is an inspection method to measure.

FIG. 14 is a side view showing the configuration of a conventional semiconductor integrated circuit assembly inspection device for performing the above inspection. In the bump 2 formed on the semiconductor chip 1, the lead 3 formed on the flexible film 4 is connected.
Chip 1 is fixed to stage 6 by vacuum suction. Reference numeral 7 is a supporting portion for holding the film with leads.
A CCD camera 5 for recognizing the position above the chip 1 enlarges the joint between the bump and the lead so as to capture the image data of that portion.

The camera 5 obtains image data by focusing on the bump or the lead upper surface, but since the camera has a certain depth of focus, if the bump upper surface is focused, the lead upper surface is also focused, and conversely. Even if you focus on, the top surface of the bump is still in focus. After that, when the image data is captured and the shapes of the bumps and leads are recognized, it is determined whether or not the leads are protruding outside the bumps. As a result, the lead misalignment after the ILB is detected.

However, if the leads are not in contact with the bumps, or if the leads are slightly floating from the bumps and the leads are not connected to the bumps, it is possible to judge whether the connection state is good or bad from the image information taken in by the camera 5. It was difficult to judge.

FIG. 15 is a lead / bump connection state diagram showing a part of the image data acquired by the camera of FIG. 16 and 17 are respectively F16-F1 in FIG.
6 shows a sectional view taken along line 6 and line F17-F17.
The connection between the lead 3a and the bump 2 in FIG. 16 is good, but in FIG. 17, the lead 3b slightly floats from the bump 2 and a connection failure occurs.

However, as shown in FIG. 15, the leads 3b and the bumps 2 are in focus due to the depth of focus of the camera 5, and the leads 3b from such minute bumps 2 are in focus.
It was not possible to detect the floating of the defect.

[0008]

As described above, conventionally,
If the lead is only in contact with the bump or is slightly floating from the bump and the connection with the bump is insufficient, it is very difficult to detect the poor connection from the image captured by the camera above the chip. There was a problem.

The present invention has been made in consideration of the above circumstances, and an object thereof is a semiconductor integrated circuit assembly inspecting apparatus and an inspecting method thereof in which even a slight floating of a lead can be recognized by image data taken from a camera. To provide.

[0010]

According to another aspect of the present invention, there is provided a semiconductor integrated circuit assembly / inspection apparatus comprising: a stage to which a semiconductor chip is fixed; and an assembly means for controlling a lead to be connected to a predetermined portion of the semiconductor chip. The image information is compared by including a camera for acquiring at least two types of the lead connection state by the assembling means and the lead connection state in the assembling means changed to a positional relationship different from the lead connection state as image information. Then, the quality of the connection between the lead and the predetermined portion is determined.

A first semiconductor integrated circuit assembly inspection method according to the present invention comprises an assembly step of controlling the leads of the TAB tape to be connected to the bumps of the semiconductor chip, and a step of connecting the leads and the bumps by the assembly step. A first step of obtaining a connection state between the lead and the bump as first image information by a camera; and changing the distance from the chip to the camera in the first step by moving the chip, The second step of obtaining the connection state of the lead and the bump as second image information by a camera and the first image information and the second image information are compared to determine whether the connection state of the lead and the bump is good or bad. And a detection step of determining.

A second semiconductor integrated circuit assembly inspection method according to the present invention comprises an assembly step of holding the TAB tape at a predetermined position and controlling the leads of the TAB tape to be connected to bumps on the semiconductor chip, and the assembly step. The first step of obtaining the connection state between the lead and the bump by the camera as the first image information by the camera, and the chip and the camera are moved while the predetermined position of the TAB tape in the assembling step is kept and the first step is performed after the movement. The second step of obtaining the connection state of the lead and the bump as the second image information at the same distance as the distance between the chip and the camera in the one step, and the first image information and the second image information. And a detecting step of comparing the lead and the bump to determine whether or not the connection state between the lead and the bump is good.

According to the present invention, after the first step, at the time of the lead displacement inspection and the lead floating test, the image is re-imaged as the second image data in a state where the positional relationship of the chip is changed with respect to the predetermined position of the TAB tape. By capturing the data,
Defocus and position shift become clear and are the targets of defect detection.

[0014]

1 is a side view showing the structure of a semiconductor integrated circuit assembly inspection apparatus according to a first embodiment of the present invention. The semiconductor chip 1 is fixed to the stage 6 by vacuum suction. Bumps formed on semiconductor chip 1
The lead 3 (3-a, 3-b) of the TAB tape formed on the flexible film 4 is connected to 2. This lead 3
The TAB tape marked with is held by the support 7. A CCD camera 5 is provided above the chip.
The stage 6 is vertically controlled by a movement control mechanism 8.

The camera 5 has each bump 2 and lead
ILB (inner lead bonding) connected to 3
Then, the connection state between the lead 3 and the bump 2 is acquired as image information. Here, the camera 5 uses the connection state between the lead 3 and the bump 2 in the positional relationship immediately after the ILB as the first image data, and further uses a different positional relationship, for example, the stage 6
Is moved to move the chip slightly downward, and the connection state between the lead 3 and the bump 2 is acquired as the second image data. Therefore, the stage 6 is controlled by the movement control mechanism 8 so as to move a predetermined distance in the direction of the arrow 18 in the drawing.

FIG. 2 is a lead / bump connection state diagram conceptually showing a part of the second image data acquired by the camera 5 of FIG. Although the cross section of the lead 3 (3a, 3b) in the extension direction is not shown, the lead 3 (3a, 3b) has a trapezoidal shape in which the width of the upper surface is narrower than the width of the lower surface. 3 and 4
Shows cross-sectional views taken along lines F3-F3 and F4-F4 of FIG. 2, respectively. The connection between the lead 3a and the bump 2 in FIG. 3 is good, but in FIG.
Is floating and a poor connection has occurred.

That is, after the first image data is obtained immediately after the ILB, the movement control mechanism 8 pulls down the stage 6 in the direction of arrow 18 while maintaining the holding position of the TAB tape 4. As a result, the lead 3a which is well bonded to the bump 2 is pulled down together with the chip 1 as shown in FIG. 3, but the lead 3b which is slightly floated from the bump 2 and is insufficiently bonded is shown in FIG. It remains in that position as shown (also shown in Figure 1).

When the second image data is taken in in such a state, as shown in the image of the bumps and leads of FIG. 2, the leads 3b floating from the bumps 2 are the same as those at the time of obtaining the first image data. The lead (3) is still in focus, but the lead 3a that is well connected to the bump 2 is out of focus and the image is out of focus.
2 cannot be recognized in the image.

According to the method of the above configuration, the connection is defective where the lead (3) can still be recognized after the chip 1 is pulled down. As described above, by utilizing the defocus of the camera, the lead floating inspection can be performed accurately and easily. The amount by which the chip 1 is pulled down must be larger than the depth of focus of the camera 5.

The depth of focus depends on the camera used and the magnification, but generally the higher the magnification, the shallower the depth of focus. If the depth of focus is shallow, the leads connected to the bumps will be out of focus even if the amount of pulling down the chip is small. However, if the depth of focus is too shallow, image recognition itself becomes difficult. For example, if the focus is on the top surface of the lead, the bump top surface is out of focus, or if the focus is on the bump top surface, the top surface of the lead is out of focus. You can choose a suitable magnification.

FIG. 5 is a side view showing the configuration of a semiconductor integrated circuit assembly inspection apparatus according to the second embodiment of the present invention.
The difference from the first embodiment is that when acquiring the second image data after ILB, the stage 6 is moved in the direction of the arrow 18 in the figure by the movement control mechanism 8 and the camera 5 is also moved by the same amount. It is being pulled down by the control mechanism 9 (arrow 19 in the figure). Therefore, the chip and the camera are moved after the first image data is acquired, and the distance between the chip and the camera is controlled to be the same after the first image data is acquired as after the movement.

FIG. 6 is a lead / bump connection state diagram conceptually showing a part of the second image data acquired by the camera 5 of FIG. 7 and 8 are respectively F7-F in FIG.
7 shows a sectional view taken along line 7 and line F8-F8. Figure 7
Although the connection between the lead 3a and the bump 2 is good,
Then, the lead 3b floats from the bump 2 and a connection failure occurs.

That is, after the first image data is acquired immediately after the ILB, the movement control mechanism 8 pulls down the stage 6 in the direction of the arrow 18 while keeping the holding position of the TAB tape 4, and accordingly the camera 5 also. It is pulled down in the direction of arrow 19 by the movement control mechanism 9. However, this movement does not change the distance between the chip 1 and the camera 5 at the lead connection position when acquiring the first image data.

As a result, the lead 3a which is well bonded to the bump 2 is pulled down together with the chip 1 as shown in FIG. 7, but the lead 3b which is slightly floated from the bump 2 and is insufficiently bonded is The position is maintained as it is as shown in FIG. 8 (also shown in FIG. 5).

When the second image data is fetched in such a state, as shown in the image of bumps and leads in FIG. 6, the camera also moves by the same amount as the chip this time, so that the bump 2 is good. The lead 3a connected to is still in focus on the lead (3) as it was when the first image data was acquired, but the lead 3b floating from the bump 2 is out of focus and the image is blurred. Lead 3a and bump 2
Can not be recognized in the image.

According to the method of the above configuration, the connection is defective where the lead (3) cannot be recognized after the chip 1 is pulled down. As a result, similarly to the first embodiment, the lead floating inspection can be performed accurately and easily by utilizing the defocus of the camera. Chip 1 and camera
The amount of pulling down 5 is the same as in the first embodiment.
It is necessary to make the depth of focus larger than the depth of focus of the camera used, and the depth of focus of the camera to be used may be appropriately selected so that image recognition is easy to some extent.

FIG. 9 is a side view showing the configuration of a semiconductor integrated circuit assembly inspection apparatus according to the third embodiment of the present invention.
The difference from the first embodiment is that the stage 6 moves in the direction of arrow 20 in the figure by the movement control mechanism 10 and the camera 5 moves by the same amount when acquiring the second image data after ILB. It is being pulled up by the control mechanism 11 (arrow 21 in the figure). Therefore, the chip and the camera are moved after the first image data is acquired, and the distance between the chip and the camera is controlled to be the same after the first image data is acquired as after the movement.

FIG. 10 is a lead / bump connection state diagram conceptually showing a part of the second image data acquired by the camera 5 of FIG. 11 and 12 are cross-sectional views taken along lines F11-F11 and F12-F12 in FIG. 10, respectively. Although the connection state between the lead 3a and the bump 2 in FIG. 11 is good, the bump 2 and the lead 3b are not joined in FIG. 12, and a connection failure occurs.

That is, after the first image data is acquired immediately after the ILB, the stage 6 is pulled up in the direction of the arrow 20 by the movement control mechanism 10 while maintaining the holding position of the TAB tape 4, and accordingly the camera 5 is also pulled. It is pulled up in the direction of arrow 21 by the movement control mechanism 11. However, this movement does not change the distance between the chip 1 and the camera 5 at the lead connection position when acquiring the first image data.

As a result, the lead 3a, which is well bonded to the bump 2, is pulled up together with the chip 1 as shown in FIG. Inadequate lead 3b is shown in Figure 12.
As shown in (1), the chip 1 is pulled up together with the chip 1, and the positional deviation occurs.

When the second image data is taken in such a state, as shown in the image of bumps and leads in FIG. 10, the camera is also moved by the same amount as the chip, so that the image is in focus. Then, the lead 3a that is well connected to the bump 2 does not have the displacement of the joint portion as it did when the first image data was acquired, but the lead 3b that floated from the bump 2 has the displacement of the joint image. Be recognized.

According to the method of the above construction, the connection is defective where the lead (3) is displaced after the chip 1 is pulled up. As a result, the lead floating inspection can be performed accurately and easily.

As described above, according to the first to third embodiments, the lead floating inspection after ILB can be performed by the position recognition camera. Thus, for example, ILB
The subsequent lead floating inspection can be performed in a short time together with the lead position deviation detection. Further, when the inner lead causing the connection failure is detected by the method shown in each of the embodiments, if the bonding step and the connection state inspection step are repeated again, the defective products due to the connection failure are drastically reduced,
The assembly yield can be dramatically improved. Further, as the camera for acquiring the image for inspection, it is possible to use only one camera used for alignment during bonding as shown in each of the above embodiments, or another dedicated camera may be used. .

Although the camera is shown to move by the movement control mechanism in the second and third embodiments,
Even if the camera itself does not move, the focus position can be changed by the amount of movement of the stage. Also, FIG.
As shown in FIG. 3, a common movement control mechanism 12 may be configured so that the stage 6 and the camera 5 move together.

[0035]

As described above, according to the present invention, the lead floating inspection after ILB can be performed simultaneously with the detection of the lead position deviation. Further, when an inner lead causing a connection failure is detected, if the bonding is performed again, the number of defective products due to the connection failure can be reduced and the assembly yield can be dramatically improved. And an inspection method can be provided.

[Brief description of the drawings]

FIG. 1 is a side view showing the configuration of a semiconductor integrated circuit assembly inspection device according to a first embodiment of the present invention.

FIG. 2 is a lead / bump connection state diagram conceptually showing a part of the second image data acquired by the camera of FIG.

3 is a cross-sectional view taken along line F3-F3 of FIG.

FIG. 4 is a cross-sectional view taken along line F4-F4 of FIG.

FIG. 5 is a side view showing a configuration of a semiconductor integrated circuit assembly inspection device according to a second embodiment of the present invention.

FIG. 6 is a lead / bump connection state diagram conceptually showing a part of second image data acquired by the camera of FIG.

7 is a cross-sectional view taken along line F7-F7 of FIG.

8 is a cross-sectional view taken along line F8-F8 of FIG.

FIG. 9 is a side view showing the configuration of a semiconductor integrated circuit assembly inspection device according to a third embodiment of the present invention.

FIG. 10 is a lead / bump connection state diagram conceptually showing a part of the second image data acquired by the camera of FIG. 9.

11 is a cross-sectional view taken along line F11-F11 of FIG.

12 is a cross-sectional view taken along line F12-F12 of FIG.

FIG. 13 is a side view showing the configuration of a semiconductor integrated circuit assembly inspection device according to an application of the second and third embodiments of the present invention.

FIG. 14 is a side view showing the configuration of a conventional semiconductor integrated circuit assembly inspection device.

FIG. 15 is a lead / bump connection state diagram showing a part of image data acquired by the camera of FIG.

16 is a cross-sectional view taken along line F16-F16 of FIG.

17 is a cross-sectional view taken along line F17-F17 of FIG.

[Explanation of symbols]

 1 ... Chip, 2 ... Bump, 3 (3a, 3b) ... Lead, 4 ... Film, 5 ... Camera, 6 ... Stage, 7 ... TAB tape support, 8, 9, 10, 11 ... Movement control mechanism.

Front page continued (72) Inventor Eiichi Hosomi 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Inside Toshiba Research & Development Center, Inc. (72) Inventor Koji Shibazaki 25-1, Ekimaehonmachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Toshiba Microelectronics Co., Ltd.

Claims (10)

[Claims] 1. A stage to which a semiconductor chip is fixed, an assembly means for controlling a lead to be connected to a predetermined portion of the semiconductor chip, a lead connection state by the assembly means, and a lead connection state different from each other. A camera that acquires, as image information, at least two types of lead connection states in the assembling means that have been changed in the positional relationship, and compares the image information to determine whether the connection state between the leads and a predetermined location is good or bad. A semiconductor integrated circuit assembly inspecting apparatus, comprising: 2. A stage to which a semiconductor chip is fixed, an assembly means for controlling a lead of a TAB tape to be connected to a predetermined portion of the semiconductor chip, and a connection state of the lead and the predetermined portion as image information. A camera to be acquired, a moving means capable of setting a first distance from the chip to the camera at a lead connection position by the assembling means, and a second distance from the chip to the camera changed from the first distance. The semiconductor integrated circuit assembly inspection, comprising: comparing the image information acquired by the camera at the first distance and the image information acquired at the second distance, and determining the quality of the connection between the lead and a predetermined location. apparatus. 3. The assembling means includes holding means for holding the TAB tape, and at the lead connection position when the first distance changes to the second distance by the moving means.
3. The semiconductor integrated circuit assembly inspection device according to claim 2, wherein the holding position of the TAB tape by the holding means is maintained as it is. 4. The semiconductor integrated circuit assembly inspection apparatus according to claim 3, wherein the change from the first distance to the second distance by the moving means is made larger than the depth of focus of the camera. 5. A stage to which a semiconductor chip is fixed, and a support means for holding a TAB tape, and assembly means for controlling the lead of the TAB tape to be connected to a predetermined portion of the semiconductor chip, and the lead and the predetermined portion. A camera that obtains the connection state with a location as image information, and the chip and the camera are moved while the position of the support portion is maintained at the lead connection position by the assembling means, and at the lead connection position by the assembling means even after the movement. And a moving unit that makes the distance equal to the distance between the chip and the camera, comparing the respective image information acquired by the camera before and after the moving unit is operated, and comparing the lead and the predetermined position. A semiconductor integrated circuit assembly / inspection device, characterized by determining whether the connection state is good or bad. 6. The distance moved by the moving means is larger than the depth of focus of the camera.
The semiconductor integrated circuit assembly inspection device described. 7. An assembly process for controlling a lead of a TAB tape to be connected to a bump of a semiconductor chip, and a connection state between the lead and the bump is first detected by a camera at a connection position of the lead and the bump in the assembly process. After changing the distance from the chip to the camera according to the first step by moving the chip,
The second connection state of the lead and the bump is measured by the camera.
And a detection step of comparing the first image information and the second image information to determine whether the connection state between the lead and the bump is good or bad. Semiconductor integrated circuit assembly inspection method. 8. An assembling step of holding the TAB tape in a predetermined position and controlling so that leads of the TAB tape are connected to bumps on a semiconductor chip, and a connection state between the leads and bumps by the assembling step is detected by a camera. And a distance between the chip and the camera in the first step after moving the chip and the camera while keeping a predetermined position of the TAB tape in the assembling step. In the same manner, the second step of acquiring the connection state of the leads and the bumps as the second image information, and comparing the first image information and the second image information with each other to determine the connection state of the leads and the bumps. A semiconductor integrated circuit assembly inspection method, comprising: a detection step of determining pass / fail. 9. The method according to claim 7, wherein when the detection step determines that there is a defect, at least the defective portion is detected again through the assembling step and the first and second steps. Semiconductor integrated circuit assembly inspection method. 10. The semiconductor integrated circuit assembly inspecting method according to claim 7, wherein the first image information and the second image information are compared with each other by using information on the defocus of the camera.